The present invention, in some embodiments thereof, relates to methods and systems for transmitting data over a single carrier wireless link, and more particularly, but not exclusively, to transmitting data over a single carrier wireless link using transmit diversity and/or receive diversity and achieving a form of space diversity.
Wireless point-to-point communication systems are deployed all over the world as a backbone of cellular networks and wireless Internet services. Cellular network backbones usually require a line-of-sight (LOS) and a regulated frequency band to ensure high availability throughout the year with no or only little interference. The required availability in such links may reach 99.999% of the year. Frequency bands commonly used are in the range between 7 GHz and 38 GHz.
Since communication is done between two stationary nodes in the network, transmission beams are often generated using dish antennas which provide some gain and reduce interference. In the lower frequency range, for example 4 GHz-15 GHz, long range links are formed. These links occasionally suffer from multipath effects which may cause either flat or dispersive fading phenomena.
A space diversity receiver combines a signal as received by two or more sufficiently spaced apart receive antennas. If a distance between receiving antennas is sufficiently large, it is assumed that multipath effect fading causes uncorrelated fading in the two receiving antennas. In a typical installation a distance between the spaced apart antennas at one side of a wireless link is on the order of 10 meters. Space diversity has proven itself over the years as an effective method to overcome multipath fading.
Additional background art includes:
U.S. Patent Application Publication number 2014/0126664 of Mizrahi et al., titled “Using Sequences for Symbol Timing Synchronization in Single-Carrier MIMO Communication Systems”.
H. Matsuda, K. Takeda and F. Adachi, “Downlink Transmit Diversity for Broadband Single-Carrier Distributed Antenna Network”, 71st IEEE Conference on Vehicular Technology, VTC 2010, Taipei.
The disclosures of all references mentioned above and throughout the present specification, as well as the disclosures of all references mentioned in those references, are hereby incorporated herein by reference.